Portable or wearable devices continue to increase in popularity, and feature increasingly sophisticated functionality. These devices need to have an input interface for the user in order to control the device, either by adding hardware in the form of electronic buttons, or by an external communication device, e.g., remote control, smart phone application, or the like. However, the use of electronic or touch screen buttons may be frustrating for the user, because it may be difficult to identify and/or use a specific button or other interface component, given the limited size of a keyboard or a screen of the device.